1 September

1902: On 1 September 1902, Dirk Brouwer was born.

Brouwer was a Dutch-born US astronomer and geophysicist known for his achievements in celestial mechanics, especially for his pioneering application of high-speed digital computers for astronomical computations.

While still a student he determined the mass of Titan from its influence on other Saturnian moons. Brouwer developed general methods for finding orbits and computing errors, and applied these methods to comets, asteroids, and planets. He computed the orbits of the first artificial satellites. His book, Methods of Celestial Mechanics, taught a generation of celestial mechanicians.

1859: On 1 September 1859, a solar flare was observed for the first time by astronomer Richard Carrington.